Quite a few transit systems do have a demonstration rack set up somewhere so you can try out the loading/unloading procedure with your bike. Call yours up and check if you still have concerns about it. But as long as your bike is a pretty normal type there shouldn't be any problem. The trough for the tires holds the bike pretty securely and keeps the front wheel from pivoting so the arm over the tire/fender does hold it in the rack very well.